I've got a 2005 Camry Altise which has this problem. When i first noticed it I took it straight back the Dealer and asked them about it and to check the car over. They said that it was something that they had heard of before but had never encountered any damage to anything on any inspections of vehicles. I did some calling around to some service centres that specialised in toyota automatic transmissions and they backed this up. If you're concerned about it, or if it's bothering you, go to a specialist and ask them if they'll tweak it.